Use of quantitative cultures and reduced duration of antibiotic regimens for patients with ventilator-associated pneumonia to decrease resistance in the intensive care unit

Treatment strategy for older patients with pneumonia independent of the risk of drug resistance in the world's top country for longevity

The number of older people with impaired swallowing function increases with aging population. Aspiration pneumonia is one of the most cases of pneumonia developing among older people. As aspiration pneumonia may develop as a result of age-related deterioration, it is crucial to consider it as an unavoidable event with aging. While pneumonia is diagnosed based on respiratory symptoms and radiological features, the lung involvement of aspiration pneumonia may be undetectable via a frontal chest radiograph in some cases. Bacterial profiles show the predominance of drug-resistant bacteria, such as Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), but isolated bacteria from respiratory samples do not necessarily indicate causative pathogens. Furthermore, there is no evidence regarding treatment superiority using broad-spectrum antibiotics compared with narrow-spectrum antibiotics. Even if isolated pathogens are a causative factor for pneumonia among older patients, the use of broad-spectrum antibiotics covering the bacteria may not improve their outcomes. Therefore, we propose a treatment strategy independent of the risk of drug resistance focusing on the discrimination of patients who are unlikely to respond to broad-spectrum antibiotics. An aspiration risk is associated with increased in-hospital mortality in patients with pneumonia, which could also lead to a greater risk of poor long-term outcomes with increased 1-year mortality. Advance care planning is now recognized as a process for communication and medical decision-making across the life course. This approach would be widely recommended for older people with aspiration risk.

Establishment of a risk prediction model for multidrug-resistant bacteria in deceased organ donors: a retrospective cohort study in China

Background

Multidrug resistance in bacteria is a serious problem in organ transplantations. This study aimed to identify risk factors and establish a predictive model for screening deceased organ donors for multidrug-resistant (MDR) bacteria.

Methods

A retrospective cohort study was conducted at the First Affiliated Hospital of Zhejiang University School of Medicine from July 1, 2019 to December 31, 2022. The univariate and multivariate logistic regression analysis was used to determine independent risk factors associated with MDR bacteria in organ donors. A nomogram was established based on these risk factors. A calibration plot, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were used to estimated the model.

Results

In 164 organ donors, the incidence of MDR bacteria in culture was 29.9%. The duration of antibiotic use ≥3 days (odds ratio [OR] 3.78, 95% confidence interval [CI] 1.62-8.81, p=0.002), length of intensive care unit (ICU) stay per day(OR 1.06, 95% CI 1.02-1.11, p=0.005) and neurosurgery (OR 3.31, 95% CI 1.44-7.58, p=0.005) were significant independent predictive factors for MDR bacteria. The nomogram constructed using these three predictors displayed good predictive ability, with an area under the ROC curve value of 0.79. The calibration curve showed a high consistency between the probabilities and observed values. DCA also revealed the potential clinical usefulness of this nomogram.

Conclusions

The duration of antibiotic use ≥3 days, length of ICU stay and neurosurgery are independent risk factors for MDR bacteria in organ donors. The nomogram can be used to monitor MDR bacteria acquisition risk in organ donors.

Factors Associated With Prolonged Antibiotic Use in the Setting of Suspected Pneumonia and Negative Bronchoalveolar Lavage Cultures

Background: Diagnostic criterion for pneumonia includes clinical data and bronchoalveolar lavage cultures (BALCx) to identify pathogens. Although ~60% of BALCx are negative, there may be reluctance to discontinue antibiotics, leading to prolonged antibiotic use (PAU). Objective: The purpose of this study is to compare outcomes of subjects with negative BALCx with PAU versus without prolonged antibiotic use (nPAU). Methods: A retrospective cohort study was conducted including subjects admitted to the intensive care unit (ICU), with suspected pneumonia, and negative BALCx. Data were compared based on length of exposure to antibiotics, PAU (antibiotics >4 days) versus nPAU (antibiotics <4 days). Results: A total of 128 subjects were included, 57 in the PAU group and 71 in the nPAU group. Baseline demographics were similar between groups. Severity of illness measured by multiple organ dysfunction scores at time of bronchoalveolar lavage (BAL) collection to final result showed a statistically significant decrease in the PAU group but not in the nPAU group. No differences were found in ICU days, ventilator-free days, or mortality; however, length of stay was longer for PAU (23 vs. 17, p = .04). In the PAU group, there were fewer BALCx results of "no growth" (23% vs. 45%, p = .04), more positive gram stains (83% vs. 60%, p = .01) and more positive non-BALCx (40% vs. 14%, p = .01). In a multivariate analysis, factors associated with PAU were positive BAL gram stains (adjusted odds ratio [aOR] 3.1, p = .037) and positive non-BALCx (aOR 4.7, p = .002). Conclusion: For subjects with suspected pneumonia and negative BALCx, positive non-BALCx and positive BALCx gram stain influenced the length of exposure of antibiotics.

Comparison of methods for measuring antibiotic consumption in an intensive care unit

Hospitals worldwide are working on minimizing unnecessary use of antimicrobials. To assess actual changes of antimicrobial usage, correct and precise measurements are necessary. This study aimed to compare data on the purchase of antibiotics from the pharmacy and the administration of antibiotics to patients, respectively, in an intensive care unit (ICU). Data were obtained from the Neurointensive Care Unit (NICU) at Rigshospitalet, Denmark. During a 23-month period, comprising 10 770 bed-days (BD), the ward purchased 16 908 defined daily doses (DDD) of antibiotics from the pharmacy, and 15 130 DDD and 41 304 individual doses were administered. Intraclass correlation coefficients (ICCs) were calculated; control and runcharts and a Bland-Altman plot were constructed. Pharmacy sales and drug administration data showed no systematic variation over time with a monthly overestimation of pharmacy sales data of 10% (95% confidence interval (CI), 6.20-14.3%) for all antibiotics, and 7% (95% CI: 1.81-11.1%) for broad-spectrum antibiotics. The antibiotic consumption, without bed-days, has a clinically acceptable ICC of >0.70 and no systematic difference is suggested by the Bland-Altman plot. In this study of a large NICU, whose antibiotic consumption varied at random, pharmacy sales data were an acceptable approximation of the actual summarized drug consumption.

Explorative Randomized Phase II Clinical Study of the Efficacy and Safety of Finafloxacin versus Ciprofloxacin for Treatment of Complicated Urinary Tract Infections

The broad-spectrum C-8-cyano-fluoroquinolone finafloxacin displays enhanced activity under acidic conditions. This phase II clinical study compared the efficacies and safeties of finafloxacin and ciprofloxacin in patients with complicated urinary tract infection and/or pyelonephritis. A 5-day regimen with 800 mg finafloxacin once a day (q.d.) (FINA05) had results similar to those of a 10-day regimen with 800 mg finafloxacin q.d. (FINA10). Combined microbiological and clinical responses at the test-of-cure (TOC) visit were 70% for FINA05, 68% for FINA10, and 57% for a 10-day ciprofloxacin regimen (CIPRO10) in 193 patients (64 for FINA05, 68 for FINA10, and 61 for CIPRO10) of the microbiological intent-to-treat (mITT) population. Additionally, the clinical effects of ciprofloxacin on patients with an acidic urine pH (80% of patients) were reduced, whereas the effects of finafloxacin were unchanged. Finafloxacin was safe and well tolerated. Overall, 43.4% of the patients in the FINA05 group, 42.7% in the FINA10 group, and 54.2% in the CIPRO10 group experienced mostly mild and treatment-emergent but unrelated adverse events. A short-course regimen of 5 days of finafloxacin resulted in high eradication and improved clinical outcome rates compared to those for treatment with ciprofloxacin for 10 days. In contrast to those of ciprofloxacin, the clinical effects of finafloxacin were not reduced by acidic urine pH. Hospitalized adults were randomized 1:1:1 to finafloxacin treatment (800 mg q.d.) for either 5 or 10 days or to ciprofloxacin treatment (400 mg/500 mg b.i.d.) for 10 days with an optional switch from intravenous (i.v.) to oral administration at day 3. The primary endpoint was the combined microbiological and clinical response at the TOC visit in the microbiological intent-to-treat population. (This study has been registered at ClinicalTrials.gov under identifier NCT01928433.).

Periprosthetic Joint Infection of Shoulder Arthroplasties: Diagnostic and Treatment Options

Periprosthetic joint infection (PJI) is one of the most frequent reasons for painful shoulder arthroplasties and revision surgery of shoulder arthroplasties. Cutibacterium acnes (Propionibacterium acnes) is one of the microorganisms that most often causes the infection. However, this slow growing microorganism is difficult to detect. This paper presents an overview of different diagnostic test to detect a periprosthetic shoulder infection. This includes nonspecific diagnostic tests and specific tests (with identifying the responsible microorganism). The aspiration can combine different specific and nonspecific tests. In dry aspiration and suspected joint infection, we recommend a biopsy. Several therapeutic options exist for the treatment of PJI of shoulder arthroplasties. In acute infections, the options include leaving the implant in place with open debridement, septic irrigation with antibacterial fluids like octenidine or polyhexanide solution, and exchange of all removable components. In late infections (more than four weeks after implantation) the therapeutic options are a permanent spacer, single-stage revision, and two-stage revision with a temporary spacer. The functional results are best after single-stage revisions with a success rate similar to two-stage revisions. For single-stage revisions, the microorganism should be known preoperatively so that specific antibiotics can be mixed into the cement for implantation of the new prosthesis and specific systemic antibiotic therapy can be applied to support the surgery.

A Standardized Regimen for the Treatment of Acute Postoperative Infections and Acute Hematogenous Infections Associated With Hip and Knee Arthroplasties

BACKGROUND

Papers concerning the treatment of periprosthetic infections and acute hematogenous infections often concern inhomogeneous treatment concepts or low numbers of patients; this results in inconsistent rates of treatment success.

METHODS

Thirty-nine patients with early periprosthetic infections and 28 patients with acute hematogenous infections were treated with a homogeneous concept and followed with a mean period of 41.8 (24-132) months in order to investigate the success rate and influencing factors. All patients were treated with open surgical debridement, a revision of all removable components and irrigation with an antiseptic solution (octinedine). All patients received a systemic vancomycin/rifampicin antibiotic therapy until the microorganism causing the infection could be identified; a specific antibiotic therapy then followed until the end of the sixth week.

RESULTS

This unified treatment regimen resulted in an overall success rate of 71.6%, an 82.1% success for early infections and 57.1% for acute hematogenous infections. Variables that influenced the recurrence of an infection were the timespan between revision and first appearance of symptoms (<2 days), the number of previous operations, the American Society of Anesthesiologists classification, and nicotine abuse.

CONCLUSION

It appears that, in cases of early postoperative infection, a reproducibly high rate of success in retaining an implant can be achieved with this specific therapy regime if surgical intervention can be carried out within 2 days of first symptoms.

Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.These guidelines are intended for use by healthcare professionals who care for patients at risk for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), including specialists in infectious diseases, pulmonary diseases, critical care, and surgeons, anesthesiologists, hospitalists, and any clinicians and healthcare providers caring for hospitalized patients with nosocomial pneumonia. The panel's recommendations for the diagnosis and treatment of HAP and VAP are based upon evidence derived from topic-specific systematic literature reviews.

Antimicrobial stewardship in hospitals: Does it work and can we do it?

Selection of resistant pathogens by antimicrobial use is probably the most important cause of antimicrobial resistance. Antimicrobial stewardship (AMS) refers to a multifaceted approach to optimise prescribing. The benefits of AMS programmes have been widely demonstrated in terms of reductions in antimicrobial use, mortality, Clostridium difficile and other healthcare-associated infections, hospital length of stay and bacterial resistance. Several kinds of interventions (i.e. restriction of drugs, pre-authorisation of certain antimicrobials, joint clinical rounds with prescribers, implementation of guidelines and education) have shown positive results. Regrettably, in most hospitals in Latin America, Asia and Africa as well as in a significant proportion of institutions in Europe and North America, essential human and material resources are scarce or absent, and teams are neither developed nor well functioning. Despite current or potential barriers, we should start or improve our already ongoing initiatives on AMS by considering the main specific problems and act accordingly with the available human and material resources. From supervising the use of specific classes of drugs to implementing more sophisticated decision support programmes, there is a wide range of possible useful interventions.

Duration and cessation of antimicrobial treatment

Shortening the duration of antimicrobial therapy is an important strategy for optimizing patient care and reducing the spread of antimicrobial resistance. It is best used in the context of an overall approach to infection management that includes a focus on selecting the right initial drug and dosing regimen for empiric therapy, and de-escalation to a more narrowly focused drug regimen (or termination) based on subsequent culture results and clinical data. In addition to reducing resistance, other potential benefits of shorter antimicrobial courses include lowered antimicrobial costs, reduced risk of superinfections (including Clostridium difficile-associated diarrhea), reduced risk of antimicrobial-related organ toxicity, and improved drug compliance. There have been relatively few randomized clinical trials that study the optimal treatment durations for such serious infections as pneumonia (community- and healthcare/hospital-acquired), complicated intra-abdominal infection, and catheter-related bloodstream infection (CRBSI). Nonetheless, a growing number of studies have explored the possibilities of reducing the duration of antimicrobial therapy for at least certain patients with these infections, under certain circumstances. Professional organizations have compiled these data and used them to develop clinical practice guidelines to aid clinicians in choosing optimal treatment durations for individual patients. Many patients with hospital-acquired pneumonia, ventilator-associated pneumonia, or healthcare-associated pneumonia can be treated for 7-8 days, while 4-7 days and 14-day treatment durations may suffice for many patients with complicated intra-abdominal infections and uncomplicated CRBSI, respectively. This article first provides a general background on the rationale and data supporting shortened courses of antimicrobial therapy, before using 3 case studies to explore the practical implications of current knowledge and treatment guidelines when making decisions about treatment duration for individual patients with healthcare-associated pneumonia, complicated intra-abdominal infection, and CRBSI.

Infections respiratoires virales à herpesviridae en réanimation

Les herpesviridae, essentiellement l’herpes simplex virus (HSV) et le cytomégalovirus (CMV), sont fréquemment détectés dans les voies aériennes des malades non immunodéprimés sous ventilation mécanique. Bien que leur présence traduise le plus souvent une réactivation virale sans réelle atteinte parenchymateuse, celle-ci peut néanmoins exister chez un certain nombre de patients. Si le diagnostic d’atteinte parenchymateuse à herpesviridae doit être étayé par une preuve histologique (effet cytopathogène spécifique), l’utilisation des outils de virologie moléculaire (amplification par polymerase chain reaction en temps réel pour estimer la charge virale) pourrait remplacer l’examen histologique dans un futur proche. La survenue d’une bronchopneumonie à HSV est associée à une réactivation du virus au niveau oropharyngé et à la présence de lésions labiales. Cette maladie semble avoir un réel impact sur l’évolution, puisqu’elle est associée à une durée de ventilation mécanique et à un séjour en réanimation prolongés. L’intérêt d’un traitement par acyclovir dans cette indication reste cependant à déterminer. Si la réactivation du CMV dans le sang est facile à détecter et associée à une évolution défavorable, la pneumonie à CMV est difficile à prouver du fait de la lourdeur des techniques diagnostiques (biopsie pulmonaire), et son impact sur le pronostic incertain. L’intérêt d’un traitement par ganciclovir dans cette indication reste aussi à démontrer.

The safety of targeted antibiotic therapy for ventilator-associated pneumonia: a multicenter observational study

PURPOSE

The aim of this study was to determine the safety of targeted antibiotic therapy (TT) in ventilator-associated pneumonia (VAP).

MATERIALS AND METHODS

This was a secondary analysis from a multicenter trial of 740 patients with suspected VAP randomized to bronchoscopy or endotracheal aspirate cultures; all received empirical broad-spectrum antibiotics. Patients were grouped by whether they received TT, defined as tailoring or discontinuing antibiotics in response to enrolment culture results.

RESULTS

For patients with a positive culture (n = 412), baseline demographics, clinical progression of infection and multiple organ dysfunction scores (MODS), and mortality were similar for those on TT (n = 320) or those who did not receive TT (NoTT) (n = 92). The TT group had more days alive and off broad-spectrum antibiotics (14.5 vs 13.2, P = .04). In patients with a negative culture (n = 327), those on TT (n = 230) had similar baseline demographics, less frequent final adjudicated diagnosis of VAP (63.0% vs 76.3%, P = .02), and less severe clinical progression of infection and MODS compared with NoTT (n = 97). The TT group had more days alive and off broad-spectrum antibiotics (15.9 vs 13.1, P < .001), lower delta MODS (2.0 vs 3.0, P = .01), fewer mechanical ventilation days (9.8 vs 14.7, P = .03), and similar mortality compared to NoTT.

CONCLUSIONS

Targeted therapy is associated with less antibiotic use and no evidence of harm in the management of patients with VAP.

Pulmonary contusions and critical care management in thoracic trauma

Many victims of thoracic trauma require ICU care and mechanical ventilatory support. Pressure and volume-limited modes assist in the prevention of ventilator-associated lung injury. Ventilator-associated pneumonia is a significant cause of posttraumatic morbidity and mortality. Minimizing ventilator days, secretion control, early nutritional support, and patient positioning are methods to reduce the risk of pneumonia.

Diagnostic strategies for nosocomial pneumonia

PURPOSE OF REVIEW

This review describes advances in clinical and microbiological modalities for diagnosis of nosocomial pneumonia and the role of biological markers.

RECENT FINDINGS

Serial assessments with the clinical pulmonary infection score identifies nonsurvivors and allows discontinuation of antibiotics when there is low suspicion of pneumonia. Studies evaluating its clinical utility show mixed results. A meta-analysis revealed that an invasive approach does not affect mortality but reduces costs, antibiotic exposure, and multidrug resistance. In contrast to these findings, a recent trial comparing nonquantitative endotracheal aspirate and quantitative bronchoalveolar lavage cultures showed similar clinical outcomes and antibiotic utilization. The role of quantitative endotracheal aspirate for diagnosis of pneumonia not related to mechanical ventilation was recently evaluated. Procalcitonin and soluble triggering receptor expressed on myeloid cells-1 aid in diagnosis, identify sepsis related to ventilator-associated pneumonia and patients with worst outcomes.

SUMMARY

The diagnostic modality chosen depends on availability, personnel experience, and the patient's clinical status. Recent guidelines support the use of quantitative cultures in an integrated clinical and microbiological algorithm. The decision to adjust antibiotics involves clinical reassessment and interpretation of culture results. Biological markers have a potential role as screening and prognostic tools.

Does invasive diagnosis of nosocomial pneumonia during off-hours delay treatment?

OBJECTIVE

We examined whether invasive lung-specimen collection-to-treatment times for intensive care unit patients with suspected ventilator-associated pneumonia (VAP) differ with to the work shift during which specimens were collected. We compared weekday day shifts and off-hours (from 6:30 p.m. to 8:29 a.m. the next day for night shifts, from Saturday 1:00 p.m. to Monday 8:29 a.m. for weekends, and from 8:30 a.m. to 8:29 a.m. the following morning for public holidays).

DESIGN AND SETTING

Single-center, observational study in the intensive care unit in an academic teaching hospital.

PATIENTS AND PARTICIPANTS

101 patients who developed 152 episodes of bacteriologically confirmed VAP.

MEASUREMENTS AND RESULTS

Of the 152 VAP episodes 66 were diagnosed during off-hours. Neither more bronchoscopy complications nor more inappropriate initial antimicrobial treatments for patients were observed between day and off-hour shifts. Indeed, the overall time from brochoalveolar lavage to antibiotic administration was shorter for off-hours than day-shifts due to shorter specimen collection-to-antibiotic prescription times, but antibiotic prescription-to-administration times were the same.

CONCLUSIONS

An invasive strategy based on bronchoscopy to diagnose VAP was not associated with a longer time to first appropriate antibiotic administration when clinical suspicion of VAP occurs during off-hours.

Development and persistence of antimicrobial resistance in Pseudomonas aeruginosa: a longitudinal observation in mechanically ventilated patients

Intubated patients frequently become colonized by Pseudomonas aeruginosa, which is subsequently responsible for ventilator-associated pneumonia. This pathogen readily acquires resistance against available antimicrobials. Depending on the resistance mechanism selected for, resistance might either be lost or persist after removal of the selective pressure. We investigated the rapidity of selection, as well as the persistence, of antimicrobial resistance and determined the underlying mechanisms. We selected 109 prospectively collected P. aeruginosa tracheal isolates from two patients based on their prolonged intubation and colonization periods, during which they had received carbapenem, fluoroquinolone (FQ), or combined beta-lactam-aminoglycoside therapies. We determined antimicrobial resistance phenotypes by susceptibility testing and used quantitative real-time PCR to measure the expression of resistance determinants. Within 10 days after the initiation of therapy, all treatment regimens selected resistant isolates. Resistance to beta-lactam and FQ was correlated with ampC and mexC gene expression levels, respectively, whereas imipenem resistance was attributable to decreased oprD expression. Combined beta-lactam-aminoglycoside resistance was associated with the appearance of small-colony variants. Imipenem and FQ resistance persisted for prolonged times once the selecting antimicrobial treatment had been discontinued. In contrast, resistance to beta-lactams disappeared rapidly after removal of the selective pressure, to reappear promptly upon renewed exposure. Our results suggest that resistant P. aeruginosa is selected in less than 10 days independently of the antimicrobial class. Different resistance mechanisms lead to the loss or persistence of resistance after the removal of the selecting agent. Even if resistant isolates are not evident upon culture, they may persist in the lung and can be rapidly reselected.